Had Anna Soubry insisted on putting her amendment to the vote – and the Speaker would surely have selected it for that purpose – Theresa May would on balance have been helped rather than harmed.

This is because although the Government would have been subject to the embarrassment of releasing papers relating to No Deal (or risk being found in contempt of Parliament), it would not endured the greater indignity of losing its own main motion.

For if Soubry’s amendment had been passed, the Prime Minister’s motion would then not have been put to the Commons at all. So it would not have been subject to defeat by 303 votes to 258.

By crafting a motion that seemed both to back the Spelman and Brady amendments passed last month – the first explicitly opposed to No Deal; the second implicitly preparded, however reluctantly, to accept it – the Government created not so much a rod as a hammer for its own back.

Lee and his like didn’t like the Brady amendment; Jenkins and his ilk didn’t like the Spelman one. Furthermore, and as we wrote yesterday morning, Olly Robbins remarks in a Brussels bar have revived fears in the ERG that Downing Street is seeking to play them.

The sum of all this is that May, having laboriously sweated her way to the top of a hill last month, has now fallen back down it. She briefly got most of the Conservative Party behind her for a vote, and has now promptly lost its backing once again.

Yesterday afternoon, Oliver Letwin was speaking in the Commons of turning the legislature into the executive, and the Commons taking control of the negotiation altogether. That would have profound and baleful constitutional implications.

Labour seems to be on the verge of a split, with some of its own MPs defying the Whip. But the Prime Minister has to lead a government, not the opposition, and her exposure to political damage is therefore greater.

The EU’s conduct since the January votes has implied that it still seeks to give her more time. Hence its decision to allow new deadlines for new discussions. Whether it will continue to do so in the light of this latest debacle remains to be seen.